Bar coded labels have been used for many years for providing coding of goods to convey desired information, such as the contents of a container, the price of the goods, origin of the goods, and so forth. A variety of equipment has been developed for reading bar code labels. An inexpensive bar code reader is provided by bar code wands. Typically, such wands have a pencil-shaped holder for housing associated electronics, illumination and light detector devices. The tip of such a wand is typically provided by a rounded jewel element. In use, the wand is positioned for wiping the jewel tip across the bar code label, for detecting the bar code as a sequence of electrical signals, for processing. Bar code labels that are repeatedly read vary in their resistance to contact damage from the jewel tip of the bar code wands. In certain applications, the environment in which a bar code label is to be used may restrict the selection of label material to materials that are subject to damage from repeated contact scanning via a bar code wand. Ceramic labels must be used in applications exposing a bar code label to high temperatures. Although ceramic labels are useful in such high temperature applications, and can withstand any outgasing in the environment, such labels are prohibitively expensive. Attempts to use metal labels in such applications, and even in less demanding applications, have shown that such labels sustain damage to the bar code printing thereon from repeated bar code wand scans by contact with the jewel tipped heads of such wands.
Non-contact beam scanners have been developed for overcoming the problems associated with contact bar code wands in reading bar coded labels. However, such scanners as laser beam scanners, typically cost more than ten times the cost of bar code wands. Accordingly, the high cost of such laser beam scanners tends to reduce the overall economies obtained from being able to use metal bar code labels without damage by repeated scans via non-contact beam scanners. Such non-contact laser beam scanners are disclosed in Shepard et al. U.S. Pat. Nos. 4,460,120; 4,736,095; 4,845,350, respectively, for example.
Other attempts have been made in the art to provide devices for protecting bar code labels. For example, Bianco U.S. Pat. No. 4,263,503, shows the use of a plate mounted over a bar code label or bar coded area on an object, with the plate having an elongated slot therethrough for exposing a sufficient portion of the bar code. The width of the slot permits a bar code wand to be wiped across the slot without touching the label, but in close enough contact to the label for reading the bar code.
Milbrett U.S. Pat. No. 4,833,306, shows another device for protecting bar code labels or tags. In this patent, a bar code tag is encapsulated beneath a transparent window of a bar code carrier attached to an associated object. In this manner, the bar code tag is protected from harsh chemical environments, but can still be read through the transparent cover by an associated bar code reader.
Sanner U.S. Pat. No. 4,288,690, shows an optical character reader consisting of a hand-held scan head 10, that is provided with a detachable illuminator 12. The illuminator 12 includes a pair of opposing light bulbs mounted in a top portion thereof on either side of an open slot 12b. The light from the light bulbs is reflected along interior downward converging side portions to exit from a truncated tip portion of the illuminator 12. A notch is cut through the tip for permitting a user to more easily position the scanner 10 over characters to be read by moving the scanner along a row of such characters. The light from the illuminator 12 is reflected back from the characters through the topmost central slot of the illuminator 12, to focusing lenses 17, for focusing the detected light upon a light sensor array 16.
The present inventor recognized the need for a relatively inexpensive device for permitting typical bar code wands to be used for reading bar codes on metal labels, for example, without damaging the bar code label. The present inventor further recognized that such a device must be very inexpensive, and adaptable for use with a variety of standard bar code wands.